Ceramic type mineral materials generally combine high strength with chemical and thermal stability. Hence they have significant utility in many products and processes. For example, ceramic-based materials are often used as supports for catalysts and as casting sands and mold materials used for the fabrication of a variety of articles in high temperature fabrication processes. Particulate ceramic materials also have significant utility as proppants in hydrocarbon recovery processes. Such materials are injected, under very high pressures, into geological structures, together with carrier fluids in a process called hydrofracturing. The injected fluid opens cracks in rock structures allowing for the passage of hydrocarbon products therethrough. The proppant materials wedge into these opened cracks and serve to maintain the integrity and permeability of the cracked structure during the extraction process. Such materials need to have high strength and chemical inertness, and should also have densities comparable to that of the carrier fluid. In addition, since these materials are used in very large amounts, their cost should be low.